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  • Improving mobile signal coverage across all 4 UK networks at two buildings on one site in Sandy, Bedfordshire

    improving mobile signal coverage

    The Challenge

    A supplier of cut flowers was looking to improve the indoor mobile coverage within the office and working areas of their factory in Sandy, Bedfordshire. Coverage was required in two locations and across all four UK networks: O2, EE, Vodafone, and Three.

    It is worth mentioning that the O2 and Vodafone signals were not identified at all at the small outbuilding in the area before installation. And there was really poor coverage in signal strength and quality at the main building.

    The Solution

    Based on floor plans, two solutions were considered. One is based on CEL-FI GO G41, and the second is based on CEL-FI QUATRA 4000e. UCtel conducted a site survey to determine the available signals on the roof of the building and to design the system which will be installed.

    UCtel strategically placed four Coverage Units to achieve the best possible signal coverage in the factory.

    Due to the building’s interior design, the use of structured cabling was the key consideration and so the CEL-FI QUATRA system of one Network Unit and four Coverage Units was installed. 

    The Installation

    UCtel recommended using the CEL-FI QUATRA 4000e to broadcast the external signal around the main building and CEL-FI GO G41 for the small outbuilding.

    • CEL-FI QUATRA 4000e System Architecture

    UCtel deploys  solutions from Nextivity. Nextivity manufactures the CEL-FI suite of cellular coverage solutions which are designed to optimise mobile signal coverage within buildings and vehicles. CEL-FI is unconditionally network safe, preventing interference with mobile operator networks. In the UK CEL-FI products are licence-exempt and fully comply with Ofcom’s UK Interface Requirement 2102 (IR2102). CEL-FI QUATRA is a distributed antenna system (DAS) hybrid solution that combines the strength of passive and active DAS technologies to deliver high-quality mobile signals in buildings. CEL-FI QUATRA delivers a mobile signal up to 1000x stronger than analogue, utilising CAT 5e/6 cabling for RF and power over ethernet, with no signal attenuation right to the perimeter of the building. 

    The CEL-FI QUATRA solution consists of a donor antenna that is installed on the roof or outdoors where the mobile signal is strongest, a network unit (NU) that  amplifies and digitises the mobile signal, and a network of coverage units (CUs) that are placed around the building to rebroadcast the boosted signal. Passive DAS segments can optionally be added to distribute the signal around the building if required. The diagram below shows an example of the QUATRA 4000e architecture.

    Schematic of the mobile signal booster system at Flamingo Flowers
    • CEL-FI GO G41 System Architecture

    The CEL-FI solution needs to receive the best available donor signal from outside and transport the signal through low-loss cable to the network repeaters that then distribute the signal through indoor antennas. 

    A system comprises: 

    ● Donor antenna installed where it can obtain the best donor signal 

    ● Low-loss cables 

    ● Repeaters to receive donor signal and boost it 

    ● Internal antennas to broadcast the boosted signal

    Diagram of the booster system across four floors at Flamingo Flowers
    • Donor Antenna Install Locations 

    One directional donor antenna was mounted on the roof of each location requiring coverage, these were secured onto existing structures and positioned aiming for the most suitable nearby cell tower. Images of both of these can be seen below.

    Donor antenna position on the main building at Flamingo Flowers
    Donor antenna position on the outbuilding at Flamingo Flowers
    • Hardware (QUATRA 4000e) Installation Location

    The QUATRA 4000e network unit was installed within the comms cab located on the first floor of the main building:

    CEL-FI network unit installed in a ceiling void at Flamingo Flowers
    • Hardware (GO G41) Installation Location

    Four G41 units (one per network) were installed on the wall within the small outbuilding of the site. 

    Booster units mounted on a wall at Flamingo Flowers
    • Main Building QUATRA 4000e Coverage Unit Locations 

    Four coverage units were installed to achieve the best signal coverage possible. The floor plans below show the locations of the units:

    Floor plan showing coverage and network unit positions at Flamingo Flowers

    CU = Coverage Unit

    NU = Network Unit

    The Results

    The work conducted by UCtel achieved excellent mobile signal coverage across all four UK networks. 

    The signal level has been vastly improved across all networks within the required areas of the factory. 

    • Post Install Signal Findings at the small outbuilding

    The table below shows the readings before installation (N/A refers to signal not having been identified):

    Table of signal readings by network at Flamingo Flowers

    The table below shows the readings post installation:

    Table of signal readings by network after installation at Flamingo Flowers

    The table below shows download and upload speed after the system was commissioned:

    Table of download and upload speeds by network at Flamingo Flowers
    • Post Install Signal Findings at the main building

    The reading below demonstrates the poor signal in terms of both strength and quality at the main building before installation:

    Signal survey charts and coverage map for Flamingo Flowers

    The readings below show the signal level improvements within the main building:

    Table of signal readings by network at Flamingo Flowers

    Download speed from the main building can also be found below.

    Table of download and upload speeds by network at Flamingo Flowers

    The client was delighted with the work UCtel conducted and the associated improvements in mobile coverage and, subsequently, ordered an installation at another site.